Impacts on Water

1. Fuels, 2. Wood-waste Breakdown Products, 3. Metals, 4. Oxygen Demand, 5. Nutrients, 6. Ammonia (nh3), 7. Solids, 8. Pesticides, 9. Nitrates, 10. Pathogens

Text A.

Wood-waste (sawdust, shavings, chips, bark, etc.) may be a useful soil conditioner, but can also have a negative effect on surface water and groundwater. Exposure to water, air and microorganisms will cause wood-waste to break down and release soluble compounds. Some of these compounds, particularly tannins, and resin acids are directly toxic to aquatic life.

Other parameters have more indirect effects on receiving waters. High BOD and COD levels in wood-waste leachate cause the depletion of oxygen levels in surface waters. In addition, the acidity of the leachate will promote the movement of metals and nutrients out of the soil and into receiving waters. Metals can bio-accumulate in fish making them unfit for human consumption. Accumulation of metals can also kill fish. Elevated nutrient levels will cause increased fungal and algal growth in surface waters. When these organisms die off, the decomposition process requires oxygen that would otherwise be available to fish and other aquatic organisms.

Text B.

This form of nitrogen is water-soluble. Because it is soluble, it does not attach to soil particles as ammonium nitrogen does, so is easily leached from the soil. Once past the root zone, nitrates can continue moving downwards to the groundwater and into drinking water supplies.

Nitrates can cause a disease in infants known as blue-baby syndrome. In this disease, nitrates are converted to nitrites in the baby’s stomach. These nitrites reduce the oxygen carrying capacity of the blood. In extreme cases, this disease can be fatal. After the baby is about six months old, the stomach becomes more like that of an adult, and this disease poses less of a threat.

The maximum allowable concentration of nitrate nitrogen as recommended in the Canadian Drinking Water Guide-lines, is 10 mg/L nitrate nitrogen (45 mg/L as nitrate). The tolerance level of livestock to nitrate nitrogen in water is higher than the health standard for humans. As much as 40 mg/L may be safe for cattle, providing feed nitrate levels are low.

Nitrates in groundwater are an early warning sign of further contamination.

Test C.

These substances (primarily nitrogen and phosphorus) accelerate eutrophication of water bodies. Nitrogen can stimulate eutrophication in lakes, but phosphorus is generally the critical limiting nutrient. In streams both nitrogen and/or phosphorus can be the limiting nutrient. The most visible effects of eutrophication are massive blooms of phytoplankton (algae). Water with an excess of nutrients is toxic to cattle and can adversely affect fish and fish habitat. The nutrients can come from either manure or fertilizer going directly into a watercourse, or nutrient rich soil eroding from fields.

Text D.

These substances in water are present in two forms: suspended or dissolved. Examples of suspended solids are clay, silt, oils, pathogens, etc., whereas dissolved solids include nutrients, metals, etc. Either form of solids can be harmful to fish, especially ammonia which will readily kill fish. Other dissolved solids can cause the BOD of the water to rise. Upon settling, suspended solids such as silt or sand can damage the gills of fish or smother the eggs of aquatic life.

Text E.

Many organic wastes including animal manures contain micro-organisms. These may include bacteria, viruses, and parasites. Some organisms in waste may be pathogenic (disease-causing) either to animals of the same or of different species. In addition, more than 100 diseases are transmissible between animals and human beings. Water may be a pathway for the transmission of disease.

Pathogens in manure cause two water quality problems. When they enter estuaries by way of runoff they contaminate shellfish beds rendering the shellfish unfit for human consumption. Pathogens from livestock waste can also contaminate surface and groundwater drinking supplies.

Text F.

Usage of these substances can pollute both surface and groundwater. Pollution occurs by runoff or leaching of soil that has adsorbed pesticides, direct application of pesticides to water, drift, and accidents such as spills. Once water is polluted, it may affect any organism living in or using the water. This includes people, domestic animals, fish, birds, plants and wildlife.

Text G.

These substances include nickel, manganese, lead, chromium, zinc, copper, iron and mercury. Trace quantities of these metals are necessary for growth of biological life. The presence of any of these metals in even slightly elevated quantities can interfere with many beneficial uses of water. Elevated levels of metals are toxic to most living things Metals may come from manure, nonagricultural organic wastes (i.e., bio-solids), waste oil, hydraulic fluids, or can be released from soils into groundwater by acidic leachates from wood-waste products.

Text H.

This chemical, which comes from urine or fertilizer, is highly toxic to fish. Runoff from over-fertilized cropland can have a high ammonia concentration. Runoff from uncovered manure piles will also contain ammonia.

Text I.

Petroleum, antifreeze, paints, solvents, hydraulic fluids, and other oil substances can be harmful in water supplies. Oil in suspension acts on the gills of fish to interfere with respiration. Petroleum destroys algae and other plankton, removing a source of fish food and oxygen. Oily substances that settle can coat the bottom of a water body, destroy organisms, and interfere with spawning areas. Soluble and suspended materials ingested by fish can taint the flavour of the flesh or have a direct toxic action on fish or fish food. If films of free oil are present they can interfere with the natural processes of stream aeration and photosynthesis. Petroleum products generally have low acute toxicity to humans and animals; however, cancer has been linked to some forms of petroleum. The most effective environmental precautions are the maintenance of storage tanks, the containment of spills, and the safe disposal of waste oil, gas and grease substances.

Text J.

When waste enters a water body, its decomposition requires oxygen. These processes remove oxygen that would otherwise be available for fish and other aquatic life. This oxygen demand is measured by either BOD (biochemical oxygen demand) or COD (chemical oxygen demand). Therefore, waste with high levels of BOD may kill fish when it enters a watercourse. The BOD of manure is about 30 times higher than that of human waste.

Exercise 4. Look through the texts above once again and find in them the words according to their definitions given below to fill in the crossword:

1 to spoil the topsoil

2. pale yellow fluid passed as waste from the body

3. organ in the body which digests food

4. substance which provides crop productivity

5. substance which is not liquid or gas, capable to keep its shape and has three dimensions

6. to pour or lose any liquid from a container

7. an approaching danger

8. a very young child

9. domestic cows, bulls, or oxen

10. living in or near water

11. poisoning

12. bluish-white metallic element

13. process of increasing in size about plants or animals

14. substance that provides food or nourishment

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Exercise 5. Read the texts above more carefully and find in them the right answer to each question given below:

1. What causes the depletion of oxygen levels in surface waters?

a. – high BOD (biochemical oxygen demand) and COD (chemical oxygen demand) levels in wood-waste leachate

b. – chemical application to parks and lawns

c. – construction erosion

2. What will the acidity of the leachate promote?

a. – storm water runoff

b. – the causing a disease in infants known as blue-baby syndrome

c. – the movement of metals and nutrients out of the soil and into receiving waters

3. Why doesn’t this form of nitrogen (NH3) attach to soil particles?

a. – because it contains micro-organisms

b. – because this form of nitrogen is necessary for growth of biological life

c. – because it is soluble, it does not attach to soil particles as ammonium nitrogen does, so is easily leached from the soil

4. When is water toxic to cattle and can adversely affect fish and fish habitat?

a. – when the process of siltation occurs over the area

b. – when it has an excess of nutrients

c. – when the septic system doesn’t work properly

5. When are metals necessary for growth of biological life?

a. – when they are released from soils into groundwater by acidic leachates from wood-waste products

b. – when they are in a trace quantity

c. – when they are in slightly elevated quantities

6. Why is it dangerous to use contaminated water?

a. – it may be a pathway for the transmission of disease

b. – oily substances that settle can coat the bottom of a water body

c. – films of free oil can interfere with the natural processes of stream aeration and photosynthesis

Exercise 6. Match the words in the left column with their associations in the right column:

1. precautionary a. erosion 2. beneficial b. rates 3. hydraulic c. demand 4. aquatic d. amount 5. dissolved e. sandstone 6. oxygen f. infestation 7. rich g. mining 8. inappropriate h. populations 9. negative i. measures 10. microbial j. effect

11. excess k. soil 12. low l. insects 13. adverse m. solids 14. disease n. life 15. soil o. precipitation 16. industrial p. zone 17. water-bearing q. fluid 18. underground r. dusting 19. saturated s. impact 20. crop t. emission

Exercise 7. In the picture below you can see different ways of damaging the environment, give the corresponding name to each of them using the following list of expressions and translate them into Russian:

Model: 1.Q. underground storage tank – поземный отстойник/ накопитель

1. underground storage tank 2. strip-mining 3. water well 4. crop dusting 5. hazardous waste disposal 6. irrigation 7. landfill 8. sewage treatment plant 9. deforestation 10. municipal sewage discharge 11. livestock waste 12. construction erosion 13. limestone

14. siltation 15. storm water runoff 16. chemical application to parks and lawns 17. marine waste 18. underground mining 19. excessive fertilizer application 20. deep-well waste disposal 21. road-salt runoff 22. mine waste pond 23. freshwater aquifer 24. soil erosion 25. industrial emission 26. water bearing sandstone